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Batch Compress PNGs with pngquant

Quantize PNG files to 256-color palettes for massive file-size reductions that are nearly invisible on screenshots and web graphics.

LinuxbatchpngcompressionpngquantMedium risk
Run pngquant --quality=65-80 --skip-if-larger --ext .png --force *.png to compress every PNG in place, skipping any file that would end up bigger.

01Command

Command
$ pngquant --quality=65-80 --skip-if-larger --ext .png --force *.png

02What it does

pngquant converts 32-bit RGBA PNGs to 8-bit palette images using dithering, typically cutting 60-80% of the size — far more than optipng's lossless shuffle. --quality=65-80 makes it refuse to write a file whose quantized quality falls below 65, and --skip-if-larger guarantees no file grows. The --ext .png --force pair overwrites files in place; combine with find -name '*.png' -exec for whole directory trees.

03Risk

RiskMedium risk
Requirementspngquant (sudo apt install pngquant / sudo dnf install pngquant)
!Warning: This is lossy quantization: gradients and photos can band. Keep originals, and skip pngquant for images that must stay lossless.

04Undo

✓No undo needed — this command does not change persistent state.

05Sources

  • pngquant README
    pngquant (GitHub) · community · 2026-09-17
    Evidence: States pngquant 'converts RGBA PNGs to 8-bit palette PNGs' with typical savings of 60-80% and lossy-but-near-transparent quality.
  • pngquant(1) — Linux man page
    Ubuntu Manpages · technical · 2026-09-17
    Evidence: pngquant man page documenting --quality min-max, --ext, --force, --skip-if-larger and in-place batch conversion of PNGs.

Last verified: 2026-09-17 · Category: Media